Giải thích các bước giải:
a/ $|x-\dfrac{3}{4}|+|-1,5|=|-1\dfrac{2}{3}|$
$⇔ |x-\dfrac{3}{4}|+1,5=\dfrac{5}{3}$
$⇔ |x-\dfrac{3}{4}|=\dfrac{5}{3}-1,5=\dfrac{1}{6}$
$⇔ \left[ \begin{array}{l}x-\dfrac{3}{4}=\dfrac{1}{6}\\x-\dfrac{3}{4}=-\dfrac{1}{6}\end{array} \right.$
$⇔ \left[ \begin{array}{l}x=\dfrac{11}{12}\\x=\dfrac{7}{12}\end{array} \right.$
b/ $\dfrac{17}{20}-|2x-\dfrac{2}{3}|=-1\dfrac{1}{5}$
$⇔ \dfrac{17}{20}-|2x-\dfrac{2}{3}|=-\dfrac{6}{5}$
$⇔ |2x-\dfrac{2}{3}|=\dfrac{17}{20}+\dfrac{6}{5}=\dfrac{41}{20}$
$⇔ \left[ \begin{array}{l}2x-\dfrac{2}{3}=\dfrac{41}{20}\\2x-\dfrac{2}{3}=-\dfrac{41}{20}\end{array} \right.$
$⇔ \left[ \begin{array}{l}x=\dfrac{163}{120}\\x=-\dfrac{83}{120}\end{array} \right.$
c/ $(-3)-|1\dfrac{2}{5}-3x|=-1,5$
$⇔ |\dfrac{7}{5}-3x|=-3+1,5=-\dfrac{3}{2}$
$⇔ \left[ \begin{array}{l}\dfrac{7}{5}-3x=-\dfrac{3}{2}\\\dfrac{7}{5}-3x=\dfrac{3}{2}\end{array} \right.$
$⇔ \left[ \begin{array}{l}x=\dfrac{29}{30}\\x=-\dfrac{1}{30}\end{array} \right.$
Chúc bạn học tốt !!!
